Jurnal Ilmu dan Teknologi Kelautan Tropis

THE IMPACT SHORELINE MODIFICATIONS ON LEKANG TURTLE (Lepidochelys olivacea) CONSERVATION ALONG COASTAL OF KULONPROGRO, INDONESIA

Waluyo — 2024-04-30

Changes in oceanographic circumstances that continue to occur will generate challenges for coastal ecology, one of which is a change in the sea-land boundary. It is possible to have an impact on the olive ridley turtles that rise to lay their eggs by changing the region of this coastal area, particularly at Trisik Beach, Kulonprogo, and Yogyakarta Special Region. The goal of this study was to use a Geographic Information System to estimate the effect of changes in the coastline on the distribution of olive ridley turtles on Trisik Beach, Kulon Progo, and Yogyakarta Special Region in 2020-2022. Digitizing the shoreline reveals changes in the coastline, which is then analyzed using Landsat 8 satellite data retrieved with ArcGIS software. The Landsat 8 photos span the years 2020-2022. Using the Digital Shoreline Analysis System (DSAS) toolbox, each image will go through area cropping or image cutting, geometric and radiometric correction, demarcation or development of a land-sea boundary line, on-screen digitalization, and automatic calculation of coastal changes. Trisik Beach's coastline alterations from 2020 to 2022 tended to create abrasion due to the shrinking beach area. The greatest average distance to a coastline alteration was -29.61 m, the smallest was -15.03 m, and the average speed of the greatest abrasion is -8.26 m/year, the smallest is -4.19 m/year, resulting in a 111,967.03 m² reduction in coastal area. The association between shoreline alterations and the distribution of olive ridley turtle nesting on Trisik Beach is quite significant, with the beach area affecting 91.3% of turtle nests and 88.5% of turtle eggs.

Distribution of Sediment Fractions and Organic Matter in Lampung Bay

Alvianita Kusumaningsih — 2024-04-30

Sediment deposition in waters is considerably influenced by coastal processes causing variations in their physical and chemical characteristics. This study reveals the size composition of sediments and organic matter in Lampung Bay sediments how deposition processes occurAnalysis of the sediment fraction was carried out based on the American Society for Testing and Materials (ASTM) standards D422-63, while the organic matter was carried out using the loss on ignition (LOI) method. The silt sand fraction (75.95-78.73%) and clay fraction (18.27-20.28%) have a higher percentage than the sand fraction (3.00-3.81%). Then, the organic content in the sediments of Lampung Bay waters ranges from 10.67-13.48%. The distribution of sediment and organic matter fractions in the waters of Lampung Bay was not significantly different between stations, which means that stations near the head of the bay (TL 1 and TL 2) had a percentage of sediment and organic matter fractions that were not significantly different from stations in the middle or towards the mouth of the bay (TL 3-TL5).

THE ECONOMIC ANALYSIS OF FISHERIES MANAGEMENT OF BIG PELAGIC FISH IN WPPNRI 715

Septa Riadi — 2024-04-30

Fisheries management is essential in striving for fish resources to be utilized optimally and sustainably and have a welfare impact. WPPNRI 715 is one of Indonesia's eleven fisheries management areas with the most significant potential in big pelagic fish with high economic value. The aim of this study was to estimate the economic value in the management of large pelagic fisheries in WPPNRI 715. The result of the research can show utilization of big pelagic fish in WPPNRI 715 is good condition and has not exceeded the Maximum Sustainable Yield (MSY) value. Additionally, economically the benefits are still in good condition. The optimal production (MSY) of big pelagic fish in WPPNRI 715 is 421 872, 11 tons. Maximum profit MEY is Rp3 065 588,97 trillion with the actual effort of 470 609 trips where optimal effort is sustainable (MSY) of 861 131 trips and economically optimal effort (MEY) of 554 902 trips. Based on the results of the study, it was stated that there were economic benefits in the utilization of large pelagic fish resources in WPPNRI 715.

Analysis of Local Salt Quality in East Aceh Regency with Various Salt Processing Methods

Muslimah — 2024-04-30

Salt is one of the local commodities produced by the people of East Aceh District. This salt is widely utilized as an additive substance in the processing of various commodities, including fish preservation and the production of “asam sunti”. The quality of salt is greatly influenced by the concentration of seawater and their processing method. The purpose of this study was to examine the effect of production salt processing methods on the quality of the salt produced and to compare the results of analysis with SNI for consumption of iodized salt. The method used in this study is a comparative research method, which compares the quality parameters of salt produced by geomembrane (G1), boiling (G2) and a combination both of them (G3). The quality parameters analyzed were water content, NaCl content, iodine content, and water insoluble portion. The results of analysis compared with the standard SNI 3556: 2016 Concerning Iodized Consumable Salt show that the water content in G1, G2, G3 is 0, 7, and 6,4 respectively, the NaCl level in G1, G2, G3 is 120, respectively. 51, 10.98, 12.29, the water insoluble portion in G1, G2, G3 was 2, 4, 2,5 respectively and the iodine content in G1, G2, G3 was 34,65, 42,49, 47,46 respectively, so it can be concluded that geomembrane production method has better salt quality compared to the boiling production method and a combination of the two. NaCl levels and iodine levels produced through the production of geomembranes have reached the established standards SNI 3556:2010 concerning Iodized consumption salt.

Indonesia Mangrove Based Ectourism Development Strategy Potential Carrying Capabilities of The Area in West Oesapa Village Kelapa Lima District, Kupang City

septinus mendrofa — 2024-04-30

Mangrove ecotourism in West Oesapa village is ecotourism located in a densely populated area, so if this ecotourism is not managed properly it will have fatal consequences for the mangrove ecosystem. This research aims to determine the suitability of mangrove ecotourism resources and also the carrying capacity of mangrove areas as well as the development strategies so that they can be taken into consideration by stakeholders in making future management policies for mangrove ecotourism. The data collection method was carried out by direct observation, interviews and also collecting data from previous research conducted in the research area, then to formulate a strategy for developing mangrove ecotourism using SWOT analysis. The results of the data analysis of the suitability of mangrove ecotourism resources are at a level corresponding to a value of 2.24 with the number of visitors in the ecotourism area according to the calculation of the area's carrying capacity of 84 people per day with an operational time of the tourist area of 8 hours per day. The direction for developing mangrove ecotourism is to implement a diversification strategy, meaning using existing strengths to take advantage of long-term opportunities to cover weaknesses (threats).

Estimation of Organic Carbon Stocks in The Mangrove Ecosystem in Mojo Village, Ulujami District, Pemalang

Ani Haryati — 2024-04-30

The mangrove ecosystem as a coastal ecosystem is important in reducing the impact of climate change, especially in absorbing CO2 gas. The mangrove forest in Mojo Village, which had the largest area in Pemalang Regency, was not only threatened by coastal erosion but also faced deforestation for shrimp pond development. Considering the high ecological function of mangroves in climate change mitigation, it was essential to calculate carbon storage estimates in this ecosystem. The methodology employed in this study involved a survey method to analyze ecological indices and estimate carbon sequestration in mangrove biomass and sediments. The Importance Value Index indicated that the Avicennia alba mangrove species exhibited higher density and canopy coverage compared to the other three found species: Sonneratia caseolaris, Avicennia marina, and Rhizophora mucronata. The high density and canopy coverage of Avicennia alba made it the mangrove species with the highest estimated carbon biomass content. The estimated carbon storage in mangrove biomass at the research site ranged from 21.55 to 144.22 tons C/ha, while the estimated carbon storage in mangrove sediments varied from 98.45 to 181.06 tons C/ha. The total carbon storage estimate in the mangrove ecosystem of Mojo Village, Pemalang, ranged from 112.43 to 247.98 tons C/ha, with an average of 155.13 tons C/ha

SPATIAL AND TEMPORAL VARIATION OF ZOOPLANKTON COMPOSITION NEAR WHALE SHARK SIGHTINGS IN PROBOLINGGO OF EAST JAVA, INDONESIA

Nurlita Putri Anggraini — 2024-04-30

Whale shark occurrence in Probolinggo differs from other Indonesian locales, suggesting a link to zooplankton availability. Zooplankton composition and whale shark emergence are the focus of this study. From December 2017 to November 2018, six observation points were made each month. A plankton net filters and lugol preserves water. Olympus CX23 microscope observations were repeated twice. The spatial analysis revealed varying whale shark numbers at each station (Chi-square test, X2 = 1418.6, P <0.05), with six sharks observed at station PR_5. Zooplankton numbers were similar at each location. Temporal analysis revealed significant differences in whale shark appearance each month (Chi-square test, X2 = 81.04, P <0.05), with March and November having the highest appearance among the three individuals. The amount of zooplankton varied (Chi-square test, X2 = 148.61, P <0.05), with the highest abundance in April and March. Whale shark appearance and zooplankton composition were not correlated (r = 0.01, P< 0.05) both geographically and temporally. Whale sharks were linked to zooplankton kinds. Results indicate whale sharks are particularly interested in Acartia sp. (r = 0.3, P < 0.05). This suggests that whale sharks' appearance is determined by their demand for food, not zooplankton availability.

Tidal Characteristic Analysis Utilizing Radar Tide Gauge in Cirebon Seawater

Mochamad Riam Badriana — 2024-04-30

Radar-based tide gauges are one approach in measuring water level offering easier installation and maintenance. Tidal data recording that has been done commonly applies tide staff or pressure tide gauge. In this study, a radar tide gauge was installed at Cirebon port, northern part of Java island, to determine the tidal characteristics in Cirebon seawaters. Water elevation data was recorded every 15 minutes from July 2022 to November 2023. The tidal component is calculated using least squares method while the tidal type is determined using the Formzahl number. The dominant tidal component known consists of semidiurnal component i.e. M2, S2, N2, K2, 2N2; diurnal component, K1, O1, P1, Q1, J1, TAU1; and shallow water component SSA components with a height of 11.98, 5.58, 2.91, 2.11, 1.45, 11.80, 3.89, 6.11, 2.08, 1.56 and 3.11 (in cm), respectively. Tidal type in the study area is mixed type prevailing Semidiurnal. The tidal range is around 0.8-1 m high with high tide conditions at 6.00-9.00 and 18.00 - 21.00, while low tide conditions are within 11.00 - 14.00 and 01.00 - 04.00. Elevation height calculation based on datum is done by combining the tidal components. Tidal measurement data using radar can be an alternative data to support and complement data recorded in Cirebon and may become a consideration for development and other maritime activities.

Analysis of Blue Swimming Crab (Portunus Pelagicus) Stocks in The Northern Java Sea, Tegal Regency and its Management Strategy

triajeng pratiwi — 2024-06-02

Tingginya nilai ekonomis rajungan dalam perekonomian mendorong peningkatan penangkapan di alam sehingga memicu terjadinya overfishing. Pendugaan stok rajungan di Kabupaten Tegal sangat minim dilakukan karena kurangnya informasi data mengenai rajungan. Penelitian ini bertujuan untuk mengetahui karakteristik dan kondisi stok rajungan (Portunus pelagicus) di Perairan Laut Jawa, Kabupaten Tegal. Pengambilan sampel sebanyak 715 ekor dari nelayan, pengepul rajungan di Desa Suradadi, Bojongsana dan Purwahamba. Dilakukan dengan menggunakan metode sampel acak (Simple Random Sampling). Sampel yang didapat dilakukan pengukuran lebar karapas dan berat tubuh rajungan. Analisis data secara manual dan menggunakan bantuan software FISAT II dikeluarkan oleh FAO-ICLARM. Diantaranya sebaran frekuensi lebar karapas, hubungan lebar berat, pola pertumbuhan, mortalitas dan laju eksploitasi serta pola rekrutmen rajungan (Portunus pelagicus). Hasil penelitian ini adalah karakteristik rajungan di Kabupaten Tegal penangkapannya menggunakan bubu lipat, jenis yang banyak ditangkap jantan dengan ukuran lebar karapas 14 cm. Kondisi stok rajungan di Kabupaten Tegal masih dikategorikan baik sebab laju eksploitasi rajungan hanya sebesar 0,31 per tahun yang menunjukkan bahwa upaya penangkapan belum melebihi batas tingkat eksploitasi maksimal yaitu 0,5 per tahun. Upaya pengelolaan rajungan di Kecamatan Suradadi, Kabupaten Tegal yaitu strategi pengelolaan perikanan rajungan di perairan Kabupaten Tegal meliputi menetapkan pengelolaan perikanan rajungan dalam Peraturan Daerah dan sosialisasi kepada stakeholder terkait.